Household refrigerators include a condensing component of the refrigeration system which has a compressor and a condenser and a fan for the forced circulation of ambient or indoor air over the condensing unit for cooling purposes. The condenser usually comprises a serpentine refrigerant tubing provided with a plurality of closely spared wire or plate-type fins mounted on or bonded to a sheet of metal. It is well known that during operation of a forced air cooled condenser of this type, foreign substances present in the stream of household air circulated over the condenser collect on the surfaces and eventually build up to an insulating layer which materially decreases the condensing capacity of the condenser.
The collection of such foreign substances on the condenser surfaces and the eventual clogging of the air passages therein constitutes a particular problem in the household refrigerator art. The foreign substances carried by or comingled with the household airstream passing over a household refrigerator condenser include not only particulate matter such as lint and dust but also a fluid component, usually an oil or grease, which not only accelerates the collection of the particulate component on the condenser surface but also prevents the circulating airstream from dislodging the lint and dust-like particles from the condenser surface once they have come in contact therewith. Because of this heterogenous composition of the foreign substances present in the household airstream, household refrigerator condensers require periodic cleaning much more frequently than condensers operating, for example, in outdoor ambients. In fact, many complaints of loss of cooling capacity are in fact due only to clogged or coated condensers. Therefore, various means have been used or proposed for preventing the loss of condenser efficiency resulting in these complaints. However, none of the means heretofore used or proposed have been completely satisfactory either from an operational or cost standpoint.
An obvious solution to the problem is the provision of an air filter ahead of the condenser. However, because of the limited space available in a household refrigerator cabinet and particularly because the average user forgets that this filter must periodically be changed or cleaned, the provision of a filtering means has usually been found to result in an actual increase, rather than a decrease, in such service calls. It has also been proposed to provide a reversible fan means on the theory that foreign substances "filtered" from the circulating airstream as the air flows in one direction will be removed from the condenser by the reversed flow of air. However, because the liquid or greasy particles in household air tend to bond the dust and lint particles to the condenser surfaces and to one another, the mere reversal of the airstream does not serve to dislodge any substantial portion thereof. Another proposed solution to this problem has been the provision of electrically operated heating means or, in order words, a "lint burner" ahead of or in contact with the condenser. However, the addition of such means materially increases the cost of the refrigerator.
The problem of maintaining the efficiency of the condenser at a high value while materially reducing the labor of repeatedly cleaning the condenser is solved by this invention.